99% Invisible – nominally about architecture and design, but actually telling the stories behind many things we take for granted every day. The host has one of the nicest voices I’ve heard on the radio (and possibly in real life).

Planet money – economics in daily life, for those of you who want some more solid stuff than the freakonomics series.

Serial – like a TV series but audio. Start with the first season investigating a murder case, and appreciate the sheer journalistic brilliance of the team.

Inflection point – interviews with successful and powerful women who are changing the world for the better.

Everything is alive – interviews with, well, inanimate objects. One of the most original podcasts around; don’t judge before you’ve listened.